In this article, I claim that the Antinomy of pure reason emerges as the result of synthetic activities that require succession. In this regard, I show that cosmological conflicts involve different kinds of representations: (1) cosmological ideas, purely conceptual representations of the unconditioned and the product of non-temporal synthetic activities; and (2) putative complete series of spatiotemporal conditions, which require temporal synthetic activities. As I show, purely conceptual representations cannot produce cosmological conflicts: The Antinomy requires the interaction of reason, understanding, and sensibility. I also discuss the maxim and principle of pure reason, how they lead to the unconditioned (and its different notions), and how the cosmological syllogism produces the Antinomy.